Connection of a gearbox cooling to the colling circuit of an engine

ABSTRACT

A vehicle transmission ( 2 ) includes a transmission housing ( 4 ), a clutch bell housing ( 6 ), and lines ( 20, 22, 36, 38 ) for a liquid cooling medium and is connected at a junction point to a vehicle engine ( 26 ). In the area of the junction point two, first coupling flanges ( 16, 18 ) are provided on the clutch bell housing ( 6 ), and two second coupling flanges ( 30, 32 ) are provided on the vehicle engine ( 6 ), which flanges can be joined for the purpose of transferring the cooling medium between the vehicle engine ( 26 ) and the vehicle transmission ( 2 ).

[0001] The invention relates to a vehicle transmission according to the main concept of claim 1.

[0002] In the cooling of a vehicle transmission and especially in the cooling of an auxiliary retarding braking system, such as a hydrodynamic retarder, for example, or an intarder that is integrated into the transmission housing, the heat that is generated during the braking process must be drawn off. At this time, heat exchangers that release the heat generated in the retarder into the environment are still being used. Integrating the retarder into the vehicle cooling system has also already been considered. The heat exchanger can thereby be arranged in a separate component on the transmission, or may be integrated into the transmission housing, installed in the tube in the housing, or the housing can be designed to have multiple walls. From DE 196 25 357 a heat exchanger that is integrated into a transmission housing is known; however, it is not connected to the vehicle cooling circuit. If the cooling of the transmission or the retarder is to be integrated into the cooling circuit of the vehicle, there must be a connection between the transmission and the engine. In current systems, the two cooling systems normally are separate.

[0003] The object of the invention is to disclose a connection between the cooling system of a transmission or retarder and the vehicle.

[0004] The object is attained with a vehicle transmission having the characterizing features of claim 1. Variations are the object of sub-claims.

[0005] On a vehicle transmission, which includes a transmission housing, a clutch bell housing and lines for a liquid cooling medium and which is connected at a junction point to a vehicle engine, two first coupling flanges are provided on the clutch bell housing in the area of the junction point, and two second coupling flanges are provided on the vehicle engine, also in the area of the junction point, whereby the second coupling flanges can be joined to the first coupling flanges for the purpose of transferring the cooling medium between the vehicle engine and the vehicle transmission. These coupling flanges can form a standard attachment flange. Via these flanges, the vehicle cooling medium flows, on the one hand, as a cool liquid to the transmission or retarder and, on the other hand, as a heated liquid back from the transmission or retarder into the vehicle cooling circuit and the main vehicle heat exchanger (radiator). For example, additional tubes, which take up space inside the vehicle and carry with them a risk of injury, when maintenance work is being performed, can be avoided, because only a short connecting flange is necessary. In one version, the first and the second flanges are arranged inside the clutch bell housing and, in another execution model, the first and the second flanges are arranged in the exterior perimeter area of the clutch bell housing. In one advantageous model the cooling medium flows from the first flanges on the clutch bell housing directly into a double-walled transmission housing or tube in the housing of the transmission. In another advantageous variation, the coolant flows from the first flanges on the clutch bell housing through tubes arranged externally on the transmission housing to the retarder. In one execution model, a heat exchanger is provided on or in the transmission housing, which absorbs the heat generated by the retarder and is connected to the vehicle cooling system to which it delivers the heat. In an execution model, the transferred cooling medium is the cooling medium from the retarder while, in another variation, the cooling medium is the working fluid of the retarder. When a retarder that uses water as its working fluid is used, the vehicle cooling medium is also the working fluid of the retarder. In one construction, the clutch bell housing is attached to the transmission housing as a separate component, in another design the clutch bell housing is integrated into the transmission housing.

[0006] The invention will be described in greater detail with reference to the drawings. These show:

[0007]FIG. 1 is a transmission with external tubes;

[0008]FIG. 2 is a transmission with lines that lie partially inside the housing; and

[0009]FIG. 3 is a transmission with flanges inside the clutch bell housing.

[0010] In FIG. 1, a transmission housing 4 of a vehicle transmission 2 is shown, which has a clutch bell housing 6 into which an input shaft 8 of the transmission 2 extends. A retarder 10 is attached to the transmission housing 4, with a retarder housing 12 being permanently affixed to the transmission housing 4. On the outer perimeter 14 of the clutch bell housing 6, two coupling flanges 16 and 18 are provided, each of which is connected to a tube 20 and 22. The tubes 20 and 22 are routed along the outer surface of the transmission housing 4, whereby they follow a reduced perimeter of the transmission housing 4, for example, in an area 24 and finally end in the retarder housing 12. The tube 20 serves, for example, to supply a cooled cooling medium to the retarder 10, while the tube 22 serves to draw off a heated cooling medium from the retarder 10. In this manner, either the retarder 10 is cooled directly in the retarder housing 12 or, if the cooling medium also serves as the working fluid for the retarder 10, the working fluid is supplied and drawn off directly. A drive engine 26 of a vehicle (not shown here), can be connected to the clutch bell housing 6. On an outer perimeter 28 of an engine housing 40, two coupling flanges 30 and 32 are attached which join the engine housing 40 in an area 34 where they are connected to the lines for the cooling medium for the engine 26. On the openings for the coupling flanges 16, 18, 30, 32, sealing devices are provided which enable a sealed transfer of a liquid cooling medium between the engine 26 and the transmission 2.

[0011] Contrary to FIG. 1, FIG. 2 has no external tubes, rather the coupling flanges 16, 18 join directly to the transmission housing 4 where they serve, for example, to supply a cooling medium to the transmission 2 itself or to supply a cooling medium or working fluid through to the retarder 10 via tubes 36, 38, (indicated by dashed lines), through a double-walled transmission housing.

[0012] In FIG. 3, the coupling flanges 16, 18, 30 and 32 are installed inside the clutch bell housing 6 or inside the outer perimeter 14 of the transmission housing 6 and inside the outer perimeter 28 of the engine housing 40. In this way, no special measures are required on the surface of the housings 4 and 40. The coupling flanges 30 and 32 are attached in the engine housing 40 to the lines there for the cooling medium of the engine 26. In the transmission housing 4, the coupling flanges 16 and 18 are attached to lines (not visible here), inside the double-walled transmission housing for the purpose of cooling the transmission 2 and/or the retarder 10.

[0013] Reference Numerals

[0014]2 vehicle transmission

[0015]4 transmission housing

[0016]6 clutch bell housing

[0017]8 input shaft

[0018]10 retarder

[0019]12 retarder housing

[0020]14 perimeter

[0021]16 coupling flange

[0022]18 coupling flange

[0023]20 tube

[0024]22 tube

[0025]24 area

[0026]26 drive engine

[0027]28 perimeter

[0028]30 coupling flange

[0029]32 coupling flange

[0030]34 area

[0031]36 tube

[0032]38 tube

[0033]40 engine housing 

1-11. (CANCELED)
 12. A vehicle transmission (2) including a transmission housing (4), a clutch bell housing (6) and tubes (20, 22, 36, 38) for a liquid cooling medium, is connected at a junction point to a vehicle engine (26), wherein at least two first coupling flanges (16, 18) are provided on the clutch bell housing (6) in the area of the junction point, each of the at least two first coupling flanges (16, 18) is connected to at least one of the tubes (20, 22 or 36, 38), by at least two second coupling flanges (30, 32) being provided on the vehicle engine (6) in the area of the junction point, whereby the second coupling flanges can be joined to the first coupling flanges (16, 18) for transferring the cooling medium between the vehicle engine (26) and the vehicle transmission (2).
 13. The vehicle transmission (2) according to claim 12, wherein the first coupling flanges (16, 18) and the second coupling flanges (30, 32) are arranged inside the clutch bell housing (6).
 14. The vehicle transmission (2) according to claim 12, wherein the first coupling flanges (16, 18) and the second coupling flanges (30, 32) are arranged on an outer perimeter (14) of the clutch bell housing (6).
 15. The vehicle transmission (2) according to claim 12, wherein the cooling medium flows from the first coupling flanges (16, 18) on the clutch bell housing (6) directly into one of a double-walled transmission housing or into the tubes (36, 38) in the housing (4) of the transmission (2).
 16. The vehicle transmission (2) according to claim 12, wherein the cooling medium flows from the first coupling flanges (16, 18) on the clutch bell housing (6) through the tubes (20, 22) that are arranged externally on the transmission housing.
 17. The vehicle transmission (2) according to claim 12, wherein a heat exchanger is provided on or in the transmission housing (4), which draws off generated heat, and is connected via the tubes (20, 22, 36, 38) and coupling flanges (16, 18, 30, 32) to a cooling system for the vehicle, to which the heat exchanger delivers the generated heat.
 18. The vehicle transmission (2) according to claim 12, wherein the cooling medium is the cooling medium for a retarder (10).
 19. The vehicle transmission (2) according to claim 12, wherein the cooling medium is a working fluid for a retarder.
 20. The vehicle transmission (2) according to claim 19, wherein the cooling medium for the vehicle is also the working fluid for the retarder (10), when the retarder (10) has water as its working fluid. 